(1) Field of the Invention
This invention relates to exercise bicycle and more particularly to bicycles at least partially powered by manual movement of the handle bars.
(2) Description of the Related Art
Manually powered bicycles as opposed to pedal powered bicycles are old and have been well known for many years.
The term bicycle is used in this application in its broadest term, i.e., any two-wheeled vehicle. However, in this application the term will be used for those two-wheeled vehicles which are powered by the physical exertions of at least one person. It will be seen by this definition that a scooter would fit within this definition as well as the vehicle more commonly referred to as a bicycle.
A particular type of manual powered bicycles is one having the handle bars oscillating at the top of the fork. The handle bars then drive a crank sprocket through a pitman. The crank sprocket is mounted to the fork and steering post of the bicycle so that it retains the same relationship to the front wheel and to the handle bars.
The front wheel is driven through a one-way clutch attached to a wheel sprocket co-axiel with the front wheel. The development of the one-way clutches are such that they have extremely low friction and therefore the wheel does not drive the sprockets when it is in the "free-wheeling mode". This is desirable.
A common problem of such bicycles is that the drive sprocket gets locked in a dead-center position. I.e., the pitman from the oscillating handle bars is aligned with the crank extending from the axle of the sprocket to the crank pin on the sprocket. In dead-center position, the handle bars can not be moved or manipulated to cause rotation of the sprocket and therefore, no motive power can be transmitted to the vehicle.
My previous two patents, 4,147,370 issued Apr. 3, 1979 and 4,189,166 issued Feb. 19, 1980, solved this problem by having a spring which moved the crank sprocket away from dead center.